Association between self-efficacy and sociodemographic and clinical variables in patients with Diabetes Mellitus

Model of study: A cross-sectional study was conducted. Objective: to evaluate the association between self-efficacy and socio-demographic and clinical variables in patients with type 2 diabetes mellitus (T2DM). Method: The sample was composed by 111 patients with T2DM in use of insulin, in primary health care units and outpatient setting in the southeast region of São Paulo state, Brazil. Sociodemographic data were gathered using validated questionnaire and clinical data were obtained from medical and health records. Self-efficacy was assessed by the Brazilian version of Insulin Management Diabetes Self-Efficacy Scale (IMDSES). The data were submitted to descrip-tive and comparative analyses using Mann-Whitney and Kruskal-Wallis to verify association be-tween sociodemographic/clinical variables and self-efficacy. Results: Self-efficacy was associ-ated with schooling level and presence of comorbidities, such as coronary artery disease, dyslipidemia, obesity, peripheral arterial disease and peripheral neuropathy. Conclusion: The findings provide support to the design some specifics interventions aimed at improving the self-efficacy of patients with T2DM on insulin use.


INTRODUCTION
Approximately 347 million people are affected by diabetes mellitus (DM) worldwide. 1 In Brazil, in 2013, it was estimated that just under 12 million in the age group of 20-79 years old were affected by DM and costs for their treatment and monitoring may reach 3.9 billion dollars a year to the government. 2,3 The development of strategies to provide behavior change and adoption of healthy prac-tices (i.e., healthy food behavior, physical activity, selfmonitoring of blood glucose, meticulous foot care and adherence to medication) is essential to manage and control the disease. 4 Sociodemographic characteristics have been observed to affect the severity of DM. Edu-cational level, for example, is a key determinant of DM mortality in both sexes, and is more rel-evant in women, while marital status also plays an outstanding role in men. 5 Increased risk of cardiovascular diseases, cancer and mortality are well stablished among patients with Type-2 Diabetes Mellitus (T2DM). 6 The literature has reported that psychosocial factors such as self-efficacy also affect -positively or negatively -the medication adherence of the patients with T2DM. Therefore, factors as perceptions related to their illness including symptoms, consequences and curability; perceptions of medications including safety concerns, convenience and their necessity; religious healing practices and beliefs; perceptions about and experiences with their healthcare providers and the healthcare system including the availability of medications and diabetes education -were perceived as barriers to adhere to drug treatment.
Nevertheless, perceived self-efficacy and social support were assessed as facilitators in engag-ing in T2DM drug treatment. 7 The self-efficacy construct refers to one's beliefs or confidence in their ability to successfully perform a task to achieve the desired outcome. 8 This construct assumes that the initiation, maintenance or withdrawal of a behavior is also influenced by the person's beliefs in his/hers ability to overcome environmental barriers to implementation. 9 Therefore, there are reports suggesting that strengthening self-efficacy relates to healthy behaviors in patients with type (T2DM). 10,11 Previous studies 10,12 have shown that self-efficacy influenced self-care behavior in Chinese and Americans patients with T2DM. However, the association between self-efficacy and sociodemographic and clinical variables in patients with T2DM in the Brazilian context has been little investigated. The elucidation of this association should provide support for the development of specific interventions aimed at improving self-efficacy of patients with T2DM.
Considering the importance of self-efficacy in the management of T2DM, this study was aimed at evaluating the association between self-effi-cacy and sociodemographic and clinical variables in T2DM outpatients.

Participants and data collection
This study enrolled 111 patients with T2DM in regular follow up at the above-mentioned set-tings, aged over 18 years old. We included T2DM oupatients on insulin use for at least one year and with oral communication skills -those capa-ble of comprehending and speaking Brazilian Portuguese in order to be interviewed. Those pa-tients with chronic complications of T2DM in the advanced stage, as chronic renal failure under-going hemodialysis, blindness, heart failure class III and IV and those patients with physical se-quelae of stroke, were excluded. The data were collected by two of the researchers (RAN and DDT) by interview, in a private room, during the interval between medical and/or nursing appointments in referenced fields of research.
The patient was initially approached to exposure the aim of the study and obtaining the agreement to engage in study by signing the Informed Consent Form. Then, the structured interview technique was used to gather sociodemographic and clinical data, as well as measure selfefficacy by application of the Brazilian version of IMDSES scale. 13 After, the complementary clinical data (length of T2DM diagnosis, comorbidities, fasting glucose and glycated hemoglobin -HbA1c) was obtained.

Sociodemographic and clinical variables
The sociodemographic and clinical data were obtained by previously validated instru-ment, 14 consisting of the items: • Sociodemographic data: gender, age, schooling (completed years of education), family arrangement, employment and personal and family monthly income in minimum wages; • Clinical data: lenght of diagnosis and treatment of T2DM, length of insulin use, number of classes of medications in use, habits (smoking) and comorbidities -hypertension, coronary artery disease (myocardial infarction or angina), stroke, dyslipidemia, obesity (evaluated by the body mass index -BMI ³ 30.0 kg/m 2 ), metabolic syndrome and peripheral arterial disease. Data on symptoms perceived over the prior month to the interview (such as involuntary weight loss, fatigue or blurred vision); signals as hyper/hypoglycemia and complications of T2DM (retinopathy and neuropathy) were en-rolled. Anthropometric data were obtained (weight, abdominal circumference height, waist circumference) and laboratorial exams results (fasting glucose and HbA1C) -were gathered if they were collected up to three months before the interview.

Insulin Management Diabetes Self-Efficacy Scale -IMDSES
The IMDSES was created in American culture by Hurley and Harvey 15 to measure self-efficacy related to self-care of DM between patients on insulin therapy. 15,16 The scale is composed of 28 items, which measure seven types of behavior: general, diet, exercise, foot care, blood glucose monitoring, insulin administration; and detection, prevention treatment of hypoglycemia/hyperglycemia. The items are distributed over three subscales: General, Diet and Insulin.

The Brazilian version of IMDSES, proposed by
Gastal et al., 13 is composed by 20 items, distributed in the same domains, since the items which presented factor loadings < 0.30 in factor analysis were excluded (12, 13, 14, 15, 16, 17, 18, and 25). In this version, the sequence of items was modified and some of them (4,8,9,22, 25 and 26) were set in affimative mode. One item (item 20) had its text slightly modified. The an-swers are rated on a Likert-type scale of four points (1=strongly agree, 2= agree, 3= disagree and 4 = strongly disagree) and the option "d not apply" was included. The scoring was obtained by the sum of the scores, which ranged from 28 to112; in the item 13 (drafted in the negative mode) reverse scoring was used for calculating the total score. For the interpreting the Brazilian version of IMDSES, the higher the score, the lower the self-efficacy.
Nevertheless, in our study, the 28-item Brazilian version was chosen, in order to allow comparison between current results and those of the original scale. Therefore, items are distributed over subscales as following: from 1 to 11, in the Diet subscale; from 12 to 18, in the Insulin subscale; and from 19 to 28, in the General subscale. The total score comprises the sum of the three subscales. The complete Brazilian version of IMDSES showed evidence of reliability by Cronbach's al-pha coefficient for Insulin (α=0.82) and Diet (α=0.64) subscales. The General subscale pre-sented α of 0.50.

Data analyses
The Statistical Package for the Social Sciences (SPSS) for Windows, version 21.0 was used for the analysis. Frequency tables, position measurements (mean, median and range) and dispersion (standard deviation) were used for the descriptive analysis of sociodemographic/clinical variables and scores of the Brazilian version of IMDSES. Reliability regarding internal consistency was estimated by Cronbach's alpha (α) coefficient and it was established α >.70 as evidence of in-ternal consistency. Mann-Whitney and Kruskal-Wallis test were used to compare self-efficacy across sociodemographic (gender, age, education, place of residence, family structure and family in-come) and clinical variables (co-morbidities symp-toms, DM complications, blood glucose and HbA1c). A significance level of 5% was adopted.

Ethical considerations
The local ethics committee approved the study (Protocol: nº 1180/2011). The authors (RAN and DDT) explained the aim of the study and procedure of data collection to potential participants.
The enrolled patients signed the Informed Consent.

RESULTS
We found a predominance of women (64.8%), whose mean age was of 58.2 (9.0) years old, with an average schooling of 6.1 (4.5) years of study, who lived with partners and/or other family members (90.9%). Regarding clinical pro-file, the average length of treatment of T2DM was 14.5 (9.2) years, with a mean insulin use length of 7.5 (6.7) years. Concerning the comorbidities, hypertension (54.1%) and obesity (64.9%) stood out. The blurred vision was the most often reported symptom (45.9%), on the month prior to the interview. The findings showed average HbA1C level above recommended (see Table 1).
The results showed higher IMDSES scores for the General subscale and for the total score, which indicate lower self-efficacy relating to self-care of diabetes ( Table 2).
The patients with lower schooling levels, which reported less than or equal to three completed years of study, had lower self-efficacy in the General subscale, compared to those who reported greater than or equal to three completed years of study (p=0.05; Mann-Whitney test) (Ta-ble 3).
The data showed smaller self-efficacy scores of IMDSES for the Diet subscale among patients with coronary artery disease (p-value=0.04) and greater self-efficacy for those who presented weight reduction (p-value=0.02). Regarding the Insulin subscale, greater self-efficacy was observed among those who had dyslipidemia (p-value=0.006). As for the General subscale, smaller self-efficacy was observed among those who had: CAD (p-value=0.02), dyslipidemia (p-value=0.01), obesity (p-value=0.04), peripheral artery disease (p-value=0.03) and peripheral neu-ropathy (p-value=0.002) (see Table 4).

DISCUSSION
This study was aimed at evaluating the association between self-efficacy and sociodemographic and clinical variables in T2DM outpatients. Note: *SD = Standard Deviation. Note: *SD = Standard Deviation. Table 3.

Comparison analysis between of Brazilian version of Insulin Management Diabetes Self-Efficacy Scale -IMDSES
and socio-demographic variables in outpatients with type 2 diabetes mellitus (T2DM) (n = 111).   Table 4.

Comparison analysis between of Brazilian version of Insulin Management Diabetes Self-Efficacy Scale -
IMDSES and clinical variables in outpatients with type 2 diabetes mellitus (T2DM) (n = 111). comorbidites (coronary artery disease, obesity, peripheral arterial disease) and peripheral neuropathy -one of the complications of T2DM.

Self-efficacy -IMDSES
The relationship between self-efficacy and the incorporation of health behavior has been explored in several studies. 17,18 As regarding the T2DM, which is a chronic disease, whose treatment imposes a significant change in patient's lifestyle, the self-efficacy has been pointed as one of the variables present in strategies used to achieve the goal of changing behavior.
In our study, when analyzing the association between self-efficacy and sociodemographic and clinical variables, there was a statistically significant association between schooling level and the General subscale of the Brazilian version of IMDSES. Similar finding has been evidenced in previous studies, 17,19 which was demonstrated that schooling level was a significant predictor of self-efficacy.
As regarding the comparison analysis between self-efficacy and clinical variables, we found statistically significant association between patients with a lower score of self-efficacy in the Insulin and General subscales of IMDSES and presence of comorbidities. A previous study, 20 which enrolled 388 patients with T2DM, showed that people without comorbidities and T2DM complications were more confident to perform the activi-ties required for T2DM treatment. However, an-other study 21 conducted with ethnically diverse individuals, showed no association between selfefficacy and comorbidities, such as hypertension and dyslipidemia.
Our study also showed higher total scores, indicating greater impairment of total self-efficacy level among the subjects who had T2DM complications. Therefore, the current data suggest that the The findings of this study subsidize a bet-ter comprehension of the association between selfefficacy and sociodemographic and clinical variables. Further studies are recommended in order to investigate self-efficacy barriers and/or facilitators to adherence to medication and nonmedication treatment of patients with T2DM.

CONCLUSION
The findings of this study suggest that low schooling level and the presence of comorbidities and complications of T2DM were significantly associated with lower self-efficacy in patients with T2DM on insulin therapy. These data subsidizes the design of specific interventions aiming at in-crease self-efficacy for the treatment and, hence, the better management of the disease in T2DM outpatients.